Question

describe blood clotting mechanism

Answer 1

Coagulation (also known as clotting) is the process by which blood changes from a liquid to a gel, forming a blood clot. ... The mechanism of coagulationinvolves activation, adhesion, and aggregation of platelets along with deposition and maturation of fibrin.

Answer 2

Blood Clotting is one of three mechanisms that reduce the loss of blood from broken blood vessels.

The three mechanisms are:

Vascular Spasm
The smooth muscle in blood vessel walls contracts immediately the blood vessel is broken. This response reduces blood loss for some time, while the other hemostatic mechanisms become active.

Platelet Plug Formation
When blood platelets encounter a damaged blood vessel they form a "platelet plug" to help to close the gap in the broken blood vessel.
The key stages of this process are: platelet adhesion
, platelet release reaction,
and platelet aggregation

Blood Clotting (Coagulation)
Blood normally remains in its liquid state while it is within the blood vessels but when it leaves them the blood may thicken and form a gel (coagulation). Blood clotting (technically 'blood coagulation') is the process by which liquid blood is transformed into a solid state.
It is a complex process involving many clotting factors incl. calcium ions, enzymes, platelets and damaged tissues, activating each other.